1. Field of the Invention
The present invention relates to an information processing apparatus, an information processing method, and a program storage medium, and more particularly, to an information processing apparatus, an information processing method, and a program storage medium, which make it possible to prevent data from being tampered or copied in an unauthorized manner.
2. Description of the Related Art
Digital technology has become very popular. As a result, various types of content data such as music data and image data are digitally recorded and reproduced onto or from a storage medium. This makes it possible to copy content data many times without resulting in degradation in image or sound quality.
However, the advance in the digital technology has created the following problems.
1. For example, digital music data can be copied from a compact disk (CD) into a hard disk of a personal computer. In this case, the music data recorded on the CD is directly recorded on the hard disk or recorded after being compressed. This makes it possible to distribute a great number of copies via a network such as the Internet.
2. There is no limitation in the maximum number of times that digital music data is copied from a CD into a hard disk of a personal computer. This makes it possible to distribute a great number of copies.
3. When digital music data recorded on a hard disk of a personal computer is copied into an external device such as a portable device, the original music data remains on the hard disk after making a copy. This makes it possible to distribute a great number of copies.
4. The problem described in (3) may be avoided if a personal computer is controlled by software such that data such as digital music data stored on a hard disk is deleted after the data has been transferred to an external device (that is, music data is moved). However, even in this case, the original data can be left on the hard disk by making a backup copy of the data stored on the hard disk onto another storage medium before moving the data and restoring the backup data onto the hard disk
5. When digital music data recorded on a hard disk of a computer is copied into an external device such as a portable device, the personal computer does not check the authorization of the external device. This makes it possible to copy digital music data into an unauthorized device.
6. When digital music data is copied from an external device such as a portable device into a personal computer, the external device does not check the authorization of software which controls the personal computer. This makes it possible to copy digital music data into a personal computer using unauthorized software.
7. In some cases, when music data is reproduced by a personal computer from a CD, ISRC (International Standard Recording Code) included in the music data is used by the personal computer to determine whether a plurality of contents are the same or not. However, some CDs do not include ISRC data. In this case, it is impossible to determine whether a plurality of contents are the same or not.
8. The various functions described above are realized on a personal computer by means of software. Therefore, if the software is tampered, it may become possible to operate the computer in a manner different from that intended by a system designer.
In view of the above, an object of the present invention is to provide a technique for preventing content data stored on a hard disk from being tampered or copied in an unauthorized manner.